The present invention relates to the field of combustion, and provides a device which is capable of efficiently atomizing both gaseous and liquid media of varying viscosities, as well as fine fluidized solids. 
The present invention provides a novel structure for improving the efficiency of combustion. Combustion efficiency is determined, in large part, by the thoroughness of the mixing of the fuel with oxygen or air. The burner of the present invention has a nozzle configuration that promotes such efficient mixing. In particular, the novel burner promotes thorough combustion due to the recirculation of gas by molecular entrainment outside the burner, due to the structure of the burner nozzle, and also due to the internal recirculation of gases within the tapered flow cone of the gas stream. 
The nozzles used in the prior art can be categorized as “internal mix” or “external mix” nozzles. An internal mix nozzle is one in which the fuel and air are mixed inside the nozzle. In an external mix arrangement, the fuel and air mix outside the nozzle. Some systems of the prior art combine the features of both styles. 
Internal mix nozzles have the advantage that they provide means for directly forcing the air and fuel to mix in a desired manner. An internal  mix nozzle may have baffling, or other internal structures, for directing the air and fuel along predetermined paths, possibly tortuous ones, and especially under pressure, so as to cause the components to mix in a controlled and complete manner. Internal mix nozzles have the disadvantage that the structure that is useful for creating a tortuous path also creates resistance to fluid flow, and thus inherently induces a pressure drop. In general, an internal mix nozzle requires more energy to force the fuel and air streams through the nozzle, as compared with an external mix nozzle. 
Another disadvantage of an internal mix nozzle is that fuel may flow backward into the oxygen or air conduit, or oxygen or air may flow backward into the fuel conduit, due to differences in pressure while in operation or from loss of pressure of either medium. Such unwanted flows can possibly cause unintended combustion or even an explosion. An external mix nozzle significantly reduces this problem, because the mixing occurs outside of the nozzle structure. 
The fuel throughput achievable with an external mix nozzle is generally greater than what is obtainable from an internal mix structure, because of the fact that most external mix nozzles do not force the fuel or air to follow tortuous paths. That is, the back pressure associated with an external mix nozzle is generally less than that experienced with an internal mix nozzle. In addition, some external mix nozzles have an external “target”, which is a barrier located beyond the nozzle tip, the target serving to redirect the pressurized stream of fuel and make it mix more efficiently with a pressurized stream containing oxygen and/or air. The target thus inherently impedes the flow of fuel, and increases the pressure drop of the nozzle, requiring additional pressure to force the fuel through the system. Also, the useful life of the burner is reduced due to heating of the target, and such a burner requires relatively exotic  materials of construction. 
In the prior art, internal mix nozzles have been used preferably for mixing a liquid with a gas, while external mix nozzles have been preferred for use in mixing gaseous media. An important advantage of the nozzle of the present invention is that it provides an external mix nozzle which is suitable for mixing virtually any combination of liquids and gases. Moreover, with the nozzle of the present invention, the need for pumping fuel under pressure is greatly reduced, while the fluid medium is still efficiently atomized. 